Available hormone-based methods of contraception are not always effective and may present serious side effects. For example, all estrogen-based therapies are known to increase the risk of endometrial hyperplasia and cancer, as well as the risk of breast cancer, in treated individuals. Even estrogen/progestin combinations designed to relieve some of the side effects of unopposed estrogen therapies result in a number of side effects, including uterine bleeding and the continuation of menstrual periods. Accordingly, there remains a need in the art to provide safer and more effective methods of contraception.